Keep the kitten in a separate room for the first few days
Provide separate food, water, litter boxes, and bedding
Swap bedding or toys so each cat gets used to the other’s scent
Feed both cats on opposite sides of a closed door
Let them hear and smell each other before face-to-face contact
Use a baby gate or cracked door for visual introductions
Start with very short supervised meetings
Keep the kitten calm and the cat relaxed during introductions
Reward calm behavior with treats and praise
End interactions before either cat becomes stressed or aggressive
Increase meeting time gradually
Never force interaction
Give the older cat safe spaces and escape routes
Keep litter boxes and resources spread out
Supervise all early interactions
Separate them if hissing, swatting, or chasing escalates
Repeat introductions over days or weeks as needed
Maintain routine and consistency for both cats
Seek veterinary or behavior help if aggression continues